A California Coptic Christian man, convicted of financial crimes, has admitted his involvement in managing and providing logistics for the production of Innocence of Muslims, the Islamophobic film that has sparked protests across Cairo, Benghazi and Sanaa.

In an interview with the AP, 55-year-old Nakoula Basseley Nakoula said he assisted the production of the film, which depicts the Prophet as an illegitimate son and feckless philander who approves of child sexual abuse.

Nakoula denied that he directed the film himself, but said he knew the elusive Jewish real estate developer Sam Bacile, who allegedly made the movie.

However AP has traced a mobile phone number, supplied by a man claiming to be Sam Bacile, to Nakoula's address, and federal court papers said the real estate specialist has previously operated under several aliases, including Nicola Bacily and Erwin Salameh.

Nakoula said Bacile supported the concerns of Christian Copts about their treatment by Muslims.

The involvement of Nakoula and Morris Sadek, a conservative US-based Coptic Christian who promoted the release, lends weight to the theory that Egypt's Coptic diaspora was behind the production of the film.

Steve Klein, an anti-Islamic activist and consultant on the film, allegedly worked closely with Coptic groups over the years, according to Jim Horn, a fellow activist quoted by the Guardian.

US pastor Terry Jones, whose threat to burn the Koran triggered riots in Afghanistan in 2010, said he also promoted Bacile's film.

Did the cast know they were making an anti-Muslim film?

The 13-minute video, posted on YouTube under the pseudonym Sam Bacile, included ineptly overdubbed scenes and revealed a summary editing technique.

A statement "on the behalf of the 80 cast and crew members", published by CNN, said they are "extremely upset and feel taken advantage of by the producer".

"We are 100% not behind this film and were grossly misled about its intent and purpose," the statement says. "We are shocked by the drastic re-writes of the script and lies that were told to all involved. We are deeply saddened by the tragedies that have occurred."

Rosie Gray, from Buzzfeed, pointed out that the film's overdubs may indicate that the footage was aimed at something completely different.

"Among the overdubbed words is 'Mohammed', suggesting that the footage was taken from a film about something else entirely," she wrote. "The footage also suggests multiple video sources - there are obvious and jarring discrepancies among actors and locations."

Actually, the actor playing Mohammed looks more like a Monty Python-like portrayal of Jesus on Life of Brian.

Gawker quoted an actress of the film, Cindy Lee Garcia from Bakersfield, California, who said she had no idea she was playing a role in a blasphemous spoof of the life of Muhammad. The script was entitled Desert Warriors, according to her.

"It was going to be a film based on how things were 2,000 years ago," Garcia said. "It wasn't based on anything to do with religion; it was just on how things were run in Egypt. There wasn't anything about Muhammad or Muslims or anything."

Muhammad was not even called like that. His role was that of a certain Master George.

UPDATE: US law enforcement has confirmed that Nakoula is the filmmaker of Innocence of Muslims